Wheel for a motor vehicle

ABSTRACT

The wheel includes an outer rim, made of a metal material, for supporting a tire, first and second annular elements, also metal, are each arranged within the rim with a circumferential skirt adjacent the rim and a perimretal edge connected to a corresponding outer edge of the rim, with an inner annular flange lying in a plane substantially orthogonal to the axis of the wheel and facing and fixed to a corresponding flange on the other annular element so as to form an annular assembly for fixing to a wheel hub; and stiffening means provided in the region defined between the rim and the circumferential skirts of said annular elements.

This is a National stage entry under 35 U.S.C. §371 of Application No.PCT/IB01/00046 filed Jan. 18, 2001; the disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a wheel for motor vehicles in general.

More specifically, the object of the invention is a wheel for a motorvehicle which includes a metal outer rim for supporting a tire.

The motor vehicle wheel of the invention is characterised in that italso includes

first and second annular elements, also both made of metal and eacharranged within the rim and having a circumferential skirt adjacent therim, with an edge connected to a corresponding edge of the rim, and aninner annular flange lying in a plane substantially orthogonal to theaxis of the wheel and facing and fixed to a corresponding flange on theother annular element so an to form an annular assembly for fixing to awheel hub, and

stiffening means provided in the region between the rim and thecircumferential claddings of the said annular elements.

According to a further characteristic, a metal spacer ring is positionedbetween the flanges of the said annular elements.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, the aforesaid stiffeningmeans include a heat resistant plastics material, a high-densitypolyurethane resin for example, injected into this region.

As well as, or as an alternative to, this plastics material, thestiffening means may also includes at least a pair of shaped metalrings, interposed between the rim and the circumferential claddings ofthe said annular elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will becomeapparent from the detailed description which follows, provided purely byway of non-limitative example, with reference to the appended drawings,in which:

FIG. 1 is an axially sectioned partial view of a motor vehicle wheel ofthe invention, and

FIG. 2 is an axially sectioned partial view of a variant of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

A wheel according to the invention is generally indicated W in FIG. 1.

This wheel includes a metal outer rim 1. Using methods known in the art,this wheel is made from a sheet of metal, in particular steel, bent intoa ring. The ends of the sheet are welded together and the ring thusconstructed is formed into the desired shape by forming and rollingoperations.

In the embodiment shown by way of example, the wheel W is a wheel for acommercial vehicle and the rim 1 has a central portion 4 which isdepressed, forming a channel between two circumferential humps 5. Thehumps 5 separate the channel portion 4 from two shoulder portions 6 and7, an outer and an inner shoulder respectively, which are provided toreceive the beads of a tire (not illustrated).

The shoulder portions 6 and 7 are connected to curved edge portions 8and 9 of the rim, which are outwardly convex.

The shape of the rim shown in the drawings is not limitative however.

The wheel W also comprises two annular elements 2 and 3, also both madeof metal, arranged within the rim 1. These annular elements 2 and 3 aremade by cutting and drawing, for example, and each have acircumferential skirt 10, 11 adjacent the rim 1 and having a perimeteredge 10, 11 a joined, by a folded seam for example, to a correspondingouter edge 8 a, 9 a of the rim 1.

Alternatively, the edges 10 a, 11 a of the annular elements 2 and 3could be fixed to the edges 8 a and 9 a of the rim 1 by welding, TIGwelding for example.

The annular elements 2 and 3 also each have an inner flange 12, 13 lyingin a plane substantially orthogonal to the axis A—A of the wheel W andeach facing and fixed to a corresponding flange 13, 12 of the otherannular element. A metal spacer ring 14, made of steel for example, ispreferably interposed between the flanges 12 and 13 of the annularelements 2 and 3.

Conveniently, the flanges 12 and 13 of the annular elements 2 and 3 arefixed to each other and to the spacer ring 14 by welding, projectionwelding for example.

The flanges 12, 13 and the spacer ring 14 form together an annularassembly 15 for fixing to a wheel hub (not illustrated). To this end, itis convenient for the assembly 15 to have openings or through-holes 16for fixing means such as bolts or the like.

In the structure as described, a region 17 is defined between the rim 1and the circumferential skirts 10 and 11 of the annular elements 2 and3.

In order to stiffen the structure of the wheel W, a heat resistantplastics material 18, such as a low-expansion or high densitypolyurethane resin, can be injected into the region 17. This plasticsmaterial can be injected through one or more of the holes formed in atleast one of the annular elements 2 or 3, such as the opening indicated19 in FIG. 1.

A valve 20 for inflating the tire can be fitted into a passage 21 formedthrough the outer portion of the rim 1 and also through the skirt 10 ofthe annular element 2, as well as through the stiffening plasticsmaterial 18, as shown in FIG. 1.

FIG. 2 illustrates a variant of the wheel according to the invention.

In this drawing, parts and elements which have already been describedhave been given the same reference letters or numbers.

In the variant of FIG. 2, two metal rings 22 and 23 are provided in theregion 17 defined between the rim 1 and the annular elements 2 and 3 asadditional means for stiffening the structure of the wheel. In theembodiment illustrated, the metal rings 22 and 23 form a channel incross section, with the concavity facing the rim 1, and are arranged atthe humps 5 in the region 17. The upper edges 22 a, 23 a respectively ofthese rings are folded over in contact with the inner surface of the rim1 and, more conveniently, are welded thereto. The bottom surface of thechannel-like portion of the stiffening rings 22 and 23 are each weldedto a corresponding portion of the skirts 10 and 11 of the annularelements 2 and 3.

In a further variant, which is not illustrated, a wheel according to theinvention may be constructed as in FIG. 2 but without the plasticsmaterial 18 in the region 17. In this case, only the stiffening rings 22and 23 reinforce the wheel structure.

The motor vehicle wheel of the invention can easily be constructed insuch a way that it weighs the same as an equivalent conventional wheelmade of a light metal alloy such as an aluminium alloy and significantlyless than a conventional pressed steel wheel.

On the other hand, the manufacturing cost of the wheel of the inventionis similar to that of a conventional pressed steel wheel andsignificantly less than that of a light alloy wheel. Thesecharacteristics make the wheel of the invention particularlyadvantageous.

Naturally, the principle of the invention remaining unchanged,embodiments and manufacturing details may vary widely from thosedescribed and illustrated purely by way of non-limitative example,without departing thereby from the scope of the invention as claimed inthe appended claims.

What is claimed is:
 1. A wheel for a motor vehicle including a rimstructure of metal material for supporting a tire, and a disc structure,also of metal material, inseparably connected with the rim structure andadapted to be detachably connected to a wheel hub; said rim structureincluding an outer rim member made of metal material; circumferentialhumps being formed in edge portions of said outer rim member; said discstructure including first and second annular elements, also of metalmaterial, each said annular element being arranged within said outer rimmember and having a circumferential skirt adjacent the outer rim memberwith a perimeter edge of said skirt connected to a corresponding edge ofsaid outer rim member; each annular element having further an annularinner flange lying in a plane substantially orthogonal to an axis of thewheel, the inner flange of one annular element being connected to thecorresponding inner flange of the outer annular element so as to form anannular disc portion adapted to be detachably connected to a wheel hub;said outer rim member and the skirts of said annular element defining aregion wherein there are arranged stiffening means including a heatresistant plastics material injected into the aforesaid region, and apair of metal rings interposed between the outer rim member and thecircumferential skirts of the said annular elements at the site of thesaid humps.
 2. A wheel according to claim 1, in which a spacer ring (14)made of a metal material is interposed between the flanges (12, 13) ofsaid annular elements (2, 3).
 3. A wheel according to claim 1, in whichsaid plastics material is a high-density polyurethane resin.
 4. A wheelaccording to claim 1, in which the said stiffening rings (22, 23) form achannel in cross section facing the outer rim member (1).
 5. A wheelaccording to claim 1, in which said annular elements (2, 3) and theouter rim member (1) are joined to each other by a folded seam alongtheir juxtaposed edges (10 a, 11 a; 8 a, 9 a).
 6. A wheel according toclaim 1, in which said annular elements (2, 3) are connected to the rim(1) by welding.
 7. A wheel according to claim 2, in which the flanges(12, 13) of said annular elements (2, 3) are fixed together to thespacer ring (14) by projection welding.
 8. A wheel according to claim 2,in which openings (16) are formed through said flanges (12, 13) of theannular elements (2, 3) and through the interposed spacer ring (14) forpassage of fixing members for fixing the wheel (w) to a wheel hub.